Crankshaft Oil Clearance Inspection/Repair

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata, 2004 Mazda MX-5 Miata, and 2003 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

Position plastigage on the top of the journals in the axial direction.
Install the main bearing cap. (Refer to ENGINE DISASSEMBLY/ASSEMBLY , CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II) , CAMSHAFT DISASSEMBLY NOTE .)
Remove the main bearing cap. (Refer to ENGINE DISASSEMBLY/ASSEMBLY , CYLINDER HEAD DISASSEMBLY/ASSEMBLY (II) , CAMSHAFT DISASSEMBLY NOTE .)

Measure the main journal oil clearance. If the clearance exceeds the maximum, replace the main bearing or grind the main journal and install the undersize bearings so that the specified oil clearance is obtained.

Standard Clearance

0.018-0.036 mm {0.0008-0.0014 in}

Maximum Clearance

0.10 mm {0.0039 in}

MAIN JOURNAL BEARING SPECIFICATION

Bearing Size - mm {in}	Bearing Thickness - mm {in}
Standard	2.007-2.025 {0.0791-0.0797}
0.25 {0.01} Undersize	2.133-2.137 {0.0840-0.0841}
0.50 {0.02} Undersize	2.258-2.262 {0.0889-0.0890}
0.75 {0.03} Undersize	2.383-2.387 {0.0938-0.0940}

Fig 1: Measuring Main Journal Oil Clearance

Courtesy of MAZDA MOTORS CORP.